NBC apologized to viewers Sunday afternoon for cutting the words "under God" from the Pledge of Allegiance which aired during their live coverage of the U.S. Open.

The broadcast began with a short video of children reciting the pledge. However, the words "under God" had been removed from the piece. Viewers immediately noticed and posted complaints on the social networking websites Facebook and Twitter.

Later during the broadcast, NBC apologized for the omission, saying the network didn't intend to offend anyone.

"We began our coverage of this final round just about three hours ago, and when we did it was our intent to begin the coverage of this U.S. Open championship with a feature that captured the patriotism of our national championship being held in our nation's capital for the third time," announcer Dan Hicks told viewers.

"Regrettably, a portion of the Pledge of Allegiance that was in that feature was edited out. It was not done to upset anyone, and we'd like to apologize to those of you who were offended by it," he said.

The American Center for Law and Justice, which focuses on constitutional law, announced on Monday it is sending a letter of protest to NBC over the omission from the pledge.

"The fact is by trying to pay tribute to our nation and its heritage, NBC crossed a troubling line and offended millions of Americans by cutting the phrase 'under God' from the Pledge of Allegiance," said Jordan Sekulow, director of Policy and International Relations at the ACLJ.

"The phrase 'under God' is not a throw-away line, an afterthought. It's been a critical part of the Pledge for more than half a century - a time-honored tradition," he said.

"NBC admits to editing out the phrase and its brief apology hours later was too little, too late," he added.

The ACLJ, which defends the constitutionality of the Pledge and the phrase 'under God' in courtrooms across America, will send NBC and the USGA a letter of protest over the Pledge incident.